thrift.py

# Copyright (c) 2016 Uber Technologies, Inc.
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from __future__ import unicode_literals
import six

from tchannel.schemes import THRIFT

from .. import io
from .. import rw


class ThriftSerializer(object):

    name = THRIFT

    _headers_rw = rw.headers(
        rw.number(2),
        rw.len_prefixed_string(rw.number(2)),
        rw.len_prefixed_string(rw.number(2)),
    )

    def __init__(self, deserialize_type):
        self.deserialize_type = deserialize_type

    def serialize_header(self, headers):
        headers = headers or {}
        result = self._headers_rw.write(headers, io.BytesIO()).getvalue()
        return result

    def deserialize_header(self, headers):
        headers = headers or {}
        if headers:
            if six.PY3 and isinstance(headers, str):
                headers = headers.encode('utf8')
            headers = io.BytesIO(headers)
            headers = self._headers_rw.read(headers)
        result = dict(headers)

        return result

    def serialize_body(self, call_args):

        # TODO - use fastbinary directly
        #
        # fastbinary.encode_binary(
        #     call_args, (call_args.__class__, call_args.thrift_spec)
        # )
        # fastbinary.decode_binary(
        #    result, TMemoryBuffer(body),(result_type, result_type.thrift_spec)
        # )
        #
        from thrift.protocol import TBinaryProtocol
        from thrift.transport import TTransport
        trans = TTransport.TMemoryBuffer()
        proto = TBinaryProtocol.TBinaryProtocolAccelerated(trans)
        call_args.write(proto)
        result = trans.getvalue()

        return result

    def deserialize_body(self, body):
        from thrift.protocol import TBinaryProtocol
        from thrift.transport import TTransport
        trans = TTransport.TMemoryBuffer(body)
        proto = TBinaryProtocol.TBinaryProtocolAccelerated(trans)

        result = self.deserialize_type()
        result.read(proto)
        return result


class ThriftRWSerializer(ThriftSerializer):

    def __init__(self, module, deserialize_type):
        """
        :param module:
            thriftrw generated module
        """
        # TODO export dumps/loads on classes in thriftrw in addition to
        # module-level dumps/loads.
        super(ThriftRWSerializer, self).__init__(deserialize_type)
        self.module = module

    def serialize_body(self, obj):
        return self.module.dumps(obj)

    def deserialize_body(self, body):
        if six.PY3 and isinstance(body, str):
            body = body.encode('utf8', errors='surrogateescape')
        return self.module.loads(self.deserialize_type, body)